The present application relates to a non-aqueous electrolyte secondary battery containing polyvinylidene fluoride and polyacrylonitrile as a binder of a negative electrode and a negative electrode.
In recent years, a number of portable electronic devices, for example, camcorders (video tape recorders), digital still cameras, cellular phones, personal digital assistants and laptop computers, each achieving a reduction in size and weight, have appeared. With respect to batteries, in particular, secondary batteries as a portable power source for such electronic devices, intensive studies have been conducted for the purpose of enhancing the energy density.
Above all, lithium ion secondary batteries using carbon for a negative electrode active material, a lithium-transition metal composite oxide for a positive electrode active material and a carbonic ester mixture for an electrolytic solution have been widely put to practical use because they are able to obtain a high energy density as compared with lead batteries and nickel-cadmium batteries which are related-art aqueous electrolytic solution secondary batteries (see, for example, JP-A-4-332479).
Here, it is proposed to use polyacrylonitrile as a binder of a negative electrode (see, for example, JP-A-2005-327630).